1. Field of the Invention
The present invention relates to an apparatus for metering and dispensing powdered product into containers and to a method for replacing a filler wheel used in such an apparatus.
2. Description of the Prior Art
Powder dispensing machines of the type with which this invention is concerned for dispensing a powdered product have a reservoir in which the powdered product is disposed. Underneath the reservoir, there is a filler wheel which has at least one metering opening into which the powdered product is placed from the storage chamber, in the filling position of the filler wheel. Next, the filler wheel is rotated into a product dispensing position, in which the product is dispensed into vials or small bottles or other containers.
Since such powder dispensing machines are required to dispense various batches containing different quantities, or because of wear and soiling, it is necessary to be able to replace the filler wheels. However, this involves very great effort and expense and in particular entails a tedious cleaning process. The storage chamber located above the filler wheel must be completely emptied before the filler wheel is removed. At present, this is accomplished by evacuating the storage chamber by suction.
It has been found that the powdered product can often not be removed completely by the suction evacuation, and thus when the filler wheel is removed, the product gets into the regions of the powder dispensing machine located under the storage chamber and causes contamination there. In addition, changing the filler wheel is very time-consuming, causing the machine to have a long down time. For replacing the filler wheel, it is also necessary to use complicated equipment for fixing the filler wheel when it is being installed and removed. Since such powder dispensing machines are used primarily for dispensing powdered pharmaceutical products, provision must be made for providing a sterile environment when the filler wheel is changed, or performing sterilization before the filler wheel is installed, and this also applies to the devices needed for changing the filler wheel.